Distributor ignition for internal combustion engines



July 13, 1943. MORAN 2,324,169

DISTRIBUTOR IGNITION FOR INTERNAL COMBUSTION ENGINES Filed July 19, 1941 2 Sheets-Sheet 1 lwvz-wron.

MART/N oR/W .z" W Liv/4 M. MORAN 2,324,169

DIQTRIBUTOR IGNITION FOR INTERNAL COMBUSTION ENGINES July 13, 1943.

2 Sheets-Sheet 2 Filed July 19, 1941 Patented July 13, 1943 DISTRIBUTOR IGNITION FOR INTERNAL COMBUSTION ENGINES Martin Moran, Cambridge, England, assignor of one-half to Simms Motor Units Limited, London, England, a company of Great Britain Application July 19, 1941, Serial No. 403,22t in Great Britain August 5, 19%

1 Claim.

This invention relates to distributor ignition for multi-cyl'nder internal combustion engines of the type in which a wiper carried by a rotor and provided with means whereby it can be connected to one terminal of a source of high tension, the other terminal of which is earthed, is operable to rotate continuously in one direction and bear successively upon a series of circumferentially arrange-d contacts each of which is capable of being electrically connected to one terminal of a sparking plug, the other terminal of which is earthed, the arrangement being such that when the ignition device is operatively connected in timed relatpnship to an internal combustion engine the respective cylinders receive a spark from their respective sparking plugs at a predetermined instant of the compression stroke of the piston of the cylinder.

In actual practice it is often found very desirable to ensure that the operator in charge of an internal combustion engine cannot drive the engine above a predetermined speed and the object of the present invention is to provide in the distributor ignition of a multi-cylinder internal combustion engine means for governing the ignition in such a manner that the speed of an engine is maintained within predetermined limits independently of the operator in charge of the engine.

According to the present invention there is provided a distributor ignition of the type referred to, wherein a contact carried by the distributor rotor and capable of being grounded is movable as the result of centrifugal action against the influence of a yielding control when the rotor is rotated about the axis thereof towards a part of or a contact electrically connected to the wiper arm, for the purpose hereinafter specified.

Further according to the present invention there is provided a distributor rotor for a distributor ignition of the type referred to, wherein a contact capable of being earthed is carried by the rotor so as to be movable as the result of centrifugal action against the influence of a yielding control towards a part of or a contact electrically connected to the wiper arm, for the purpose hereinafter specified.

Again, the present invention comprises the use in a distributor ignition of the type referred to of a contact which is capable of being earthed and which is movable as the result of centrifugal action against a yielding control towards a part of or a contact electrically connected to the wiper arm, for the purpose hereinafter specified.

The invention will be more particularly described with reference to drawings, in which- Figure 1 illustrates, in section along the line A-B of Figure 2, a distributor ignition constructed in accordance with the present invention,

Figure 2 is a plan View of Figure 1,

Figure 3 is an enlarged sectional elevation on the line C-D of Figure 4 of a distributor rotor constructed in. accordance with the present invention,

Figure 4 is a plan View of Figure 3, and

Figure 5 is a sectional elevation on the line EF of Figure 4.

Referring to the distributor ignition illustrated in Figures 1 and 2 of the drawings, a source of high tension voltage, not shown, is connected by a lead I through a contact 2 to the wiper arm 4% of a distributor rotor 5. The contact 2 is arranged to bear yieldingly upon a yielding portion 3 of the wiper arm ii. The wiper arm is mounted upon the rotor body 8 which is carried by a spindle 6 and is arranged to rotate continuously in one direction with the spindle 5 such a manner that periodically the wiper arm 4 engages with one of the yieldin contacts I which are connected to the sparking plugs, not shown, of a multi-cylinder internal combustion engine. In the example illustrated in Figures 1 and 2 it will be observed that the distributor is constructed for an S-cylinder engine.

Referring more particularly to the distributor rotor illustrated in Figures 3, 4 and 5, the wiper 4 is mounted upon the rotor body 8 which is arranged to be secured to the spindle 6 by screws l0 extending through the housing 8 into tapped holes ll formed in a plate i2 secured to the distributor spindle ii in any desired manner. A pin :3 formed on the plate i2 is arranged to extend into a hole formed in the rotor body 8 so as to ensure that when the rotor body 8 is screwed down upon the plate it the wiper arm 4 is in its correct angular position relatively to the spindle 6. Formed in the rotor body 8 is a cylindrical passage it which is arranged so as to extend at right angles to the axis of rotation of the wiper arm 4 in such a manner that the axis of the cylindrical passage intersects the axis of rotation of the wiper arm The wall of the cylindrical passage i4 is either formed of or lined with a heat-resisting material of low coefficient of friction for a purpose hereinafter specified and it is found that a suitable material for such a purpose is glass and therefore in the embodiment of the invention illustrated in Fi ures the accompanying 3 and of the drawings the passage I4 is illustrated as being provided with a glass liner I5. Mounted at the end of the liner I5 is a strip of conducting material which is electrically connected to the wiper arm 4 and which also extends across the cylindrical passage it. Mounted at the end of the cylindrical passage remote from the strip of conducting material 16 is a tapped element I! arranged to receive a screw l8 to which is connected a tension spring l9 which carries at its free end a contact in the form of a plunger 20. The spring l9 and the contact are therefore housed in the cylindrical passage l4 formed in the rotor body 8. The screw 18 is provided with a lock nut 2| for regulating the amount of tension which has to be overcome by centrifugal action before the contact 20 can affect the potential of the wiper arm 4. The wiper arm 4 is provided with a yieldable contact 3 which engages with the high tension contact 2 of the distributor head and forms a connection between the high tension lead and the wiper arm 4,

The contact 23 is connected through the screw i8 and the tapped element H with a lead 23 which forms an electrical connection with one of the screws I5, thereby providing the contact 20 with means whereby it can be connected to earth by screwing the screw l5 into the plate l2 of the spindle B.

It will be observed that with the construction of distributor rotor illustrated in Figures 3, 4 and 5, if the rotor is rotated about itsaxis, the contact 29 will, against the yielding control exercised by the spring [9, move under centrifu gal force along the cylindrical passage M towards the strip of conducting material I6 and will therefore, when earthed, bring the influence of the earth to prevail upon the wiper arm 4. If the distributor rotor is mounted in a distributor in the manner indicated in Figures 1 and 2 it will be found that as the contact 20 approaches the strip of conducting material I6 so the voltage of the wiper arm will be after a predetermined period, decreased, thereby reducing the speed of the engine. When the speed of the engine falls below the predetermined value the contact 20 will, under the influence of the tension spring l9, move away from the strip of material [6 and the potential at the wiper arm 4 will return to normal.

It will be observed that by having the movable contact located actually within the wiper arm there are no external elements which can be easily manipulated by the driver of the vehicle so as to prevent the control of the wiper arm coming into effect and if necessary there may be provided upon the rotor body 8 a cover 24 which can be locked to the said housing, thus preventing an unauthorized person from interfering with the adjustment of the contact 20.

When the rotor body is formed of a material such as hard rubber the wall of the passage 14 in proximity to the strip of material l6 must be made of a heat-resisting material because the sparks occasioned between the contact 20 and the strip of material It at certain speeds of the engine are liable to cause the hard rubber to burn and furthermore the wall of the passage should be formed of a material of low coefiicient of friction because with a material such as hard rubber the passage is not smooth enough for the easy working of the contact 20, but it must be appreciated that it is essential that the wall of the cylindrical passage should be heat-resisting adjacent the strip It and be formed of a material of low coefficient of friction.

Thus it will be seen that according to the present invention there is provided a distributor rotor which by adjusting the tension on the spring l9 by means of the adjusting screw l8 and by maintaining such a tension by locking the adjusting screw 18 by means of the lock nut 25 the maximum speed of the engine may be maintained within predetermined limits and by providing means for preventing the operator of the engine from interfering with the adjustment of the contact 20 it is possible to provide a distributor rotor which definitely ensures that the engine speed will not exceed a predetermined limit and which enables the governor to be housed in the rotor body in such a manner that it is impossible for an unauthorized person to interfere with the same.

What I claim as my invention and desire to secure by Letters Patent of the United States is: A centrifugal speed controlling means for an ignition system comprising a rotatable shaft, a rotor fixed on the shaft and having a transverse passage extending through the periphery thereof, a switch contact having one end embedded in the rotor and intersecting said passage and projecting through the periphery of the rotor, a wiper arm electrically connected to the projecting portion of said switch contact, a yieldable contact member carried by the wiper arm for coaction with the high tension lead-in contact of the distributor head, a device carried by the rotor and having adjustable connection in one end of said passage, an electrical conductor leading through the rotor to the rotor shaft, and a yieldably mounted contact member movably mounted in said passage and having supporting connection with said adjustable device and operable under the influence of centrifugal action incident to rotation of the rotor to engage the aforesaid switch contact upon the development of a predetermined speed. to decrease the voltage through said high tension lead-in contact and ground it.

MARTIN MORAN. 

